1. Field of the Invention
This invention relates to the manufacture of gaseous mixtures comprising H.sub.2 and CO, e.g., synthesis gas, fuel gas, and reducing gas by the partial oxidation of pumpable slurries of solid carbonaceous fuels in a liquid carrier and/or liquid or gaseous hydrocarbon fuels. In one of its more specific aspects, the present invention pertains to switching from one type of fuel to another without interruption of the process.
2. Description of the Prior Art
In the operation of a partial oxidation synthesis gas generator when the principal fuel becomes unavailable or in short supply and it is desired to operate the gas generator with a substitute or stand-by fuel, then previously it was necessary to depressurize the system and shut down the gas generator while the burner is changed and other adjustments are made to the system to provide for the new fuel. By the subject process, such costly down-time is avoided.
Annulus-type burners have been employed for introducing liquid hydrocarbonaceous fuels into a partial oxidation gas generator. For example, coassigned U.S. Pat. No. 3,528,930 shows a single annulus burner, and coassigned U.S. Pat. Nos. 3,758,037 and 3,847,564 show double annulus burners. To obtain proper mixing, atomization, and stability of operation a burner is sized for a specific throughput. Should the type of fuel feedstream change substantially, ordinarily shut-down of the system is required to replace one burner with another. Such costly shut-downs are avoided by the subject process and control system. The more complex process for preheating a gas generator by means of a preheat burner, removing the preheat burner from the gasifier, and inserting a separate production burner is described in coassigned U.S. Pat. No. 4,113,445.